package day6;

import java.util.Scanner;

/**
 * @author oldliu
 * @since 1.0
 */
public class StrTest4 {
    public static void main(String[] args) {
        StringBuilder sb=new StringBuilder();
        sb.append("你好");
        sb.append(Math.PI);
        sb.append(2>1).append(Math.random());
        System.out.println(sb);
        sb.delete(2,5);
        System.out.println(sb);
        Scanner sc=new Scanner(System.in);
        char c = sc.next().charAt(0);
        System.out.println(c);
    }
}
